1. Field of the Invention
The present invention relates generally to the field of orthopaedics, and, more particularly, to a method of making a metal-backed acetabular implant for a hip prosthesis.
2. Description of the Related Art
A conventional hip prosthesis is primarily composed of an acetabular implant and a femoral implant. The acetabular implant typically includes a generally hemispherical dome-like or cup-like metallic shell secured within the acetabulum and a dome-like or cup-like plastic or ceramic bearing secured within the shell. Accordingly, the shell typically includes an exterior configured to be anchored into the acetabulum and further typically includes an interior configured to align and retain the bearing, while the bearing typically includes an exterior configured to cooperate with the interior of the shell to align and secure the bearing within the shell and further typically includes an interior defining an artificial hip socket (which may or may not be off-centered from the exterior of the bearing, depending on the particular design). The femoral implant typically includes an elongated metallic spike or post at one end and a metallic ball at the other. The post is typically configured to be anchored into the distal femoral medullary canal and the ball is typically configured to insert into the artificial socket. Pivotal freedom of the ball within the socket allows articulation of the prosthetic joint.
A substantial dislocation and/or rotation of the bearing relative to the shell can potentially degrade the biomechanics and/or wear characteristics of the conventional hip prosthesis. Historically, balancing the needs for effective bearing retention with competing desires for design simplicity and versatility has been challenging.